Diffraction by a half plane in a compressible homogeneous plasma

Abstract

Abstract : An exact solution, developed by means of the Wiener-Hopf technique, is given for the electromagnetic (optical) and pressure (acoustic) fields generated by a plane wave incident on a perfectly conducting half plane imbedded in a homogeneous, warm plasma. From an asymptotic evaluation by the method of steepest descent, it is found that in addition to reflected optical and acoustic plane waves coupled at the boundary, and to a cylindrically spreading diffraction field appearing to emanate from the edge and penetrating both the illuminated and geometric-optical shadow regions, there exist edge diffraction effects in the form of surface waves and lateral waves. Relevant characteristics of these wave species are described and interpreted in simple physical terms via ray optical techniques. Some numerical data are also given. Although the plasma model is idealized, the results should be useful in predicting wave excitation phenomena to be associated with edge singularities. (Author)